Evaluation of CO2-fixation capacity in Sugi (Cryptomeria japonica) canopy
Grant-in-Aid for Scientific Research (B).
|Research Institution||KYUSHU UNIVERSITY|
斉藤 明 九大, 農学部, 教授 (30253511)
GYOKUSEN Koichiro KYUSHU UNIVERSITY, Faculty of agriculture, Associate Prof., 大学院・農学研究院, 助教授 (80205062)
SAKUTA Kotaro KYUSHU UNIVERSITY, Faculty of agriculture, Assistant Prof., 大学院・農学研究院, 助手 (10274523)
|Project Fiscal Year
1998 – 2000
Completed(Fiscal Year 2000)
|Budget Amount *help
¥5,500,000 (Direct Cost : ¥5,500,000)
Fiscal Year 2000 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1999 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1998 : ¥3,700,000 (Direct Cost : ¥3,700,000)
|Keywords||Sugi / Branch structure / Leaf distribution / Leaf nitrogen distribution / CO2-fixation / スギ / 枝構造 / 葉量分布 / 窒素分布 / 炭酸ガス固定 / 樹冠 / 散光 / 全光 / 光合成速度 / 林冠 / 葉内窒素 / 積算葉面積指数 / 蒸散速度 / 間伐 / 炭酸ガス固定機能 / 葉面積指数 / 吸光係数|
To reveal the CO2-fixation capacity of Sugi (Cryptomeria japonica D.Don) canopy, (1) branch structure which determine the leaf distribution, (2) leaf nitrogen distributin in a crown which determine the leaf productivity were investiqated.
(1) branch structure
Branch density and branch distribution in an individual sugi crown were determined hereditarily, and these branch characteristics can be used as parameters of crown structure model.
The branches attached at the upper and middle parts of a crown had the space spreading function and the lower branches had the spcace filling function.
Thinning had not affected the crown shape, but leaf mass and their distribution had changed. We concluded that thinning has an effect on leaf productivity by changing leaf mass and their position.
The growth of stem and branch had decreased after pruning. The decreasing rate of branch growth was smaller than that of shoot, then the crown shape had changed to an umbrella type. This phenomena can be explained as a rearrangement of leaves for the compensation of photosynthetic organ loss.
(2) Leaf nitrogen distribution
Nitrogen content of a current year leaves decreased according to light intensity decrease, then nitrogen content of upper crown was high and that of lower crown was low. Nitrogen content of old leaves was low and constant.
The effect of growing site on leaf nitrogen content was investigated. Leaf nitrogen content in a crown was under the control of two parameters, namely, light intensity and site index. These two parameters can be used as main factors affecting leaf nitrogen content in a crown.
A model for estimating CO2-fixation of a Sugi canopy was constructed using leaf nitorogen distribution and leaf photosynthesis parameters. This model was applied to a some sugi stand and the calculation result was sufficiant for explaining the stand's data.
Research Output (6results)